Found astronomy: "I'm in teh dots, connecting them."

2012-05-31_12-44-40_342
http://www.flickr.com/photos/waiferx/7315166890/
Originally uploaded by Waifer X

Detail from Adam "Ape Lad" Koford's Connect the Dots installation at Cuesta College North County Campus, Paso Robles, CA.

Star party: transit of Venus, June 5, 2012

120605-1310651
http://www.flickr.com/photos/waiferx/7343614368/
Originally uploaded by Waifer X

Briquetta, a Miniature Schnauzer, observes the June 5, 2012 transit of Venus through a Coronado Personal Solar Telescope. Photo by Cuesta College Physical Sciences Division instructor Dr. Patrick M. Len.

Star party: transit of Venus, June 5, 2012

2012-06-05_15-55-48_825
http://www.flickr.com/photos/waiferx/7158003431/
Originally uploaded by Waifer X

Transit of Venus, June 5, 2012, taken with a Motorola Atrix 4G (MB860) smartphone camera through a Meade LX200 8" reflector at Cuesta College North County campus, Paso Robles, CA. Photo by Cuesta College Physical Sciences Division instructor Dr. Patrick M. Len.

Astronomy quiz archive: solar system

Astronomy 210 Quiz 7, spring semester 2012
Cuesta College, San Luis Obispo, CA

Section 30674, version 1
Exam code: quiz07n4rS
Section 30674

0- 8.0 :	* [low = 6.0]
8.5-16.0 :	****
16.5-24.0 :	*********
24.5-32.0 :	******* [mean = 24.8 +/- 8.0]
32.5-40.0 :	********* [high = 36.5]

Section 30676, version 1
Exam code: quiz07sPh3
Section 30676

0- 8.0 :	*** [low = 3.0]
8.5-16.0 :	***********
16.5-24.0 :	******* [mean = 19.8 +/- 8.5]
24.5-32.0 :	*******
32.5-40.0 :	*** [high = 36.5]

Presentation: "Using 'Wordles' to Stimulate Student-Teacher Interactions" (SCAAPT spring 2012)

Contributed talk presented at the Southern California Section of the American Physics Association of Teachers Spring 2012 meeting, April 21, 2012, 3:45 PM, room ARTS 240, California State University-San Marcos, San Marcos, CA.

Myself.

First off, let's have some audience participation with the classic "Astronomy in the Marketplace" activity (D. Schatz, "Why Should We Care About Exploding Stars?" Universe in the Classroom, no. 8, Spring 1987 (http://www.astrosociety.org/education/publications/tnl/08/stars2.html).

Turn to your neighbor, and list some astronomy-related name brands you would find at a supermarket. Think of food-related brand names, and non-food related brand names.

From the first day of instruction for introductory astronomy at Cuesta College, here is the word tag cloud generated by Wordle.net for food-related astronomy brand names. Frequently-listed brands are larger, while brand names used only once are smallest. How many of these brand names were you able to list? Anyone have brand names not listed here?

Non-food related astronomy brand names listed by Cuesta College students. Again, how many of these brand names were you able to list? Anyone have brand names not listed here?

Let's take a look at more specific examples of using word tag clouds to generate student-teacher discussion.

Cuesta College introductory astronomy students were prompted to list words and concepts associated with "big bang" before instruction on this topic. Note how much larger explosion and theory are more than expansion.

This was also done following the quiz on cosmology, where students listed expansion and theory much larger than explosion.

Another example of how word tag clouds are used to stimulate student-teacher discussion is where Cuesta College (algebra-based) physics students listed topics they found interesting from the first midterm, which includes kinematics, Newton's laws, and circular motion.

These students were also prompted to list confusing topics as well. Note the differences in how friction, Newtonslaws, projectilemotion, and circularmotion are shown in the interesting and confusing word tag clouds.

Let's take a closer look at the process of generating word tag clouds. SurveyMonkey.com is used to assign and collect reading quizzes to prepare students before coming to lecture. Here it is used to prompt for word tags associated with Mars.

These words/phrases are lightly edited, and then put into the Wordle.net interface to generate a tag cloud.

And to close, a word tag cloud generated for the text of the presentation abstracts at this meeting. Note the predominant word: students.

Kudos: enjoyed the class

"I enjoyed the class" by Student 8166
Astronomy 210L
May 2012
Cuesta College, San Luis Obispo, CA

Physics midterm problem: unknown resistor with voltmeter, ammeter

Physics 205B Midterm 2, spring semester 2012
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 18.75

An ideal 12.0 V emf source is connected to two ideal light bulbs, an ideal resistor, an ideal voltmeter and an ideal ammeter, as shown at right. The voltmeter has a reading of 4.2 V, and the ammeter has a reading of 0.50 A. The two light bulbs have the same resistance r. Determine the resistance R of the resistor. Show your work and explain your reasoning.

Solution and grading rubric:

• p:
  Correct. Applies Kirchhoff's loop rule and Ohm's law to find the voltage drop across the resistor R = 12.0 V - 4.2 V = 7.8 V, such that its resistance R = ΔV/I = (7.8 V)/(0.50 A) = 16 Ω.
  
• r:
  Nearly correct, but includes minor math errors. May have confused voltmeter reading as absolute voltage value, rather than voltage difference.
  
• t:
  Nearly correct, but approach has conceptual errors, and/or major/compounded math errors. May have included all three resistor voltage drops in same loop rule equation, but at least demonstrates a methodical application of Kirchhoff's rules, Ohm's law, and equivalent resistance.
  
• v:
  Implementation of right ideas, but in an inconsistent, incomplete, or unorganized manner.
  
• x:
  Implementation of ideas, but credit given for effort rather than merit.
  
• y:
  Irrelevant discussion/effectively blank.
  
• z:
  Blank.
  

Grading distribution:
Section 30882
Exam code: midterm02B1rD
p: 9 students
r: 7 students
t: 10 students
v: 1 student
x: 0 students
y: 0 students
z: 0 students

A sample "p" response (from student 4027), methodically applying Kirchhoff's junction and loop rules:
Another sample "p" response (from student 0514), explicitly applying Ohm's law to the resistor R, given the voltmeter and ammeter readings:

Physics midterm problem: total magnetic field of two current-carrying wires

Physics 205B Midterm 2, spring semester 2012
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 19.71

[20 points.] Two long straight wires carry currents of equal magnitude, but heading in opposite directions. The wires are shown perpendicular to the plane of this page. The magnetic field at point P has a magnitude and direction of 1.3×10^–6 T in the +y direction. Calculate the amount of current in wire 2, and its direction. Show your work and explain your reasoning.

Solution and grading rubric:

• p = 20/20:
  Correct. Determines directions of the magnetic fields of each current separately at point P, where B₂ (larger in magnitude, generated by the nearer I₂ current) points up, and B₁ points down, such that I₂ must point out of the page (and I₁ points into the page). Then finds the magnitude of the currents by equating the total magnetic field magnitude to the arithmetic difference of the magnitudes of the two magnetic fields generated by I₁ and I₂.
  
• r = 16/20:
  Nearly correct, but includes minor math errors.
  
• t = 12/20:
  Nearly correct, but approach has conceptual errors, and/or major/compounded math errors. Equates the total magnetic field magnitude to the arithmetic sum of the magnitudes of the two magnetic fields generated by I₁ and I₂.
  
• v = 8/20:
  Implementation of right ideas, but in an inconsistent, incomplete, or unorganized manner. As (t), but explanation of I₂ current direction incorrect or missing; or sets total magnetic field magnitude equal to the magnetic field generated by I₂ only.
  
• x = 4/20:
  Implementation of ideas, but credit given for effort rather than merit.
  
• y = 2/20:
  Irrelevant discussion/effectively blank.
  
• z = 0/20:
  Blank.
  

Grading distribution:
Section 30882
Exam code: midterm02B1rD
p: 7 students
r: 2 students
t: 4 students
v: 13 students
x: 1 student
y: 0 students
z: 0 students

A sample "p" response (from student 3389):

Overhead: Earth awesomeness/lameness?

Astronomy 210L, spring semester 2012
Cuesta College, San Luis Obispo, CA

(Overheard while students set up their research posters for the last astronomy lab meeting.)

Student 1: "I hate Venus--Venus is such a lame planet."

Student 2: (Presenting a project tracking the sidereal motion of Venus.) "Nuh-uh. Venus is cool."

Instructor: "Yeah, Venus is so cool, Earth is so lame."

Student 1: "Are you kidding? Earth is awesome--it has a moon."

Instructor: (Beat.) "Earth only thinks it's awesome...it's like, 'I'm so special, check out my moon,' and the moon is like, 'Why do I hang around with this loser? If I could leave Earth I could be a planet.'"

Astronomy midterm question: comparing different apparent magnitude, distance stars

Astronomy 210 Midterm 2, spring semester 2012
Cuesta College, San Luis Obispo, CA

[20 points.] An astronomy question on an online discussion board(*) was asked and answered:

Tilly: Which star [has a brighter absolute magnitude]? Please help! :)?
Star A, apparent magnitude [+9.0], ...distance of 10 pc.
Star B, apparent magnitude [+6.5], ...distance of 1,000 pc.
Charles From Collection Agency: Star A.

Decide whether or not if this answer is correct, and how you know this. Explain using the properties of apparent magnitude, absolute visual magnitude, and distance.

*Source: http://answers.yahoo.com/question/index?qid=20081002050219AAMlBzk.

Solution and grading rubric:

• p = 20/20:
  Correct. Understands difference between apparent magnitude (m) values and absolute magnitude (M_V) values, and that Star A, 10 parsecs away will have M_V = m = +9. Star B, which at 1,000 parsecs is much further away already has a brighter apparent magnitude, and thus would have a much brighter absolute magnitude if were relocated to only 10 parsecs away.
  
• r = 16/20:
  Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors.
  
• t = 12/20:
  Contains right ideas, but discussion is unclear/incomplete or contains major errors. At least understands the difference between m and M_V values with respect to star distances, and that smaller positive (or more negative) magnitudes are brighter.
  
• v = 8/20:
  Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Garbled definitions/relations between d, m, and M_V.
  
• x = 4/20:
  Implementation/application of ideas, but credit given for effort rather than merit.
  
• y = 2/20:
  Irrelevant discussion/effectively blank.
  
• z = 0/20:
  Blank.
  

Grading distribution:
Section 30674
Exam code: midterm02n4Rg
p: 23 students
r: 2 students
t: 1 student
v: 7 students
x: 0 students
y: 0 students
z: 0 students

A sample "p" response (from student 7070):
Another sample "p" response (from student 0329), attempting to apply the Stefan-Boltzmann law, but instead illustrating the apparent magnitudes and absolute magnitudes:
An excerpt from yet another sample "p" response (from student 0359), illustrating what would happen if Star B were to be moved to 10 parsecs away from Earth: